Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757218Ab3ILUjg (ORCPT ); Thu, 12 Sep 2013 16:39:36 -0400 Received: from www.linutronix.de ([62.245.132.108]:32811 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755538Ab3ILUjf (ORCPT ); Thu, 12 Sep 2013 16:39:35 -0400 Date: Thu, 12 Sep 2013 22:39:27 +0200 (CEST) From: Thomas Gleixner To: Daniel Vetter cc: Peter Zijlstra , Dave Airlie , Maarten Lankhorst , Thomas Hellstrom , intel-gfx , dri-devel , Linux Kernel Mailing List , Ingo Molnar Subject: Re: [BUG] completely bonkers use of set_need_resched + VM_FAULT_NOPAGE In-Reply-To: Message-ID: References: <20130912150645.GZ31370@twins.programming.kicks-ass.net> <20130912154329.GB31370@twins.programming.kicks-ass.net> <20130912162210.GE31370@twins.programming.kicks-ass.net> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1011 Lines: 26 On Thu, 12 Sep 2013, Daniel Vetter wrote: > On Thu, Sep 12, 2013 at 10:20 PM, Thomas Gleixner wrote: > >> I think for ttm drivers it's just execbuf being exploitable. But on > >> drm/i915 we've > >> had the same issue with the pwrite/pread ioctls, so a simple > >> glBufferData(glMap) kind of recursion from gl clients blew the kernel > >> to pieces ... > > > > And the only answer you folks came up with is set_need_resched() and > > yield()? Oh well.... > > The yield was for a different lifelock, and that one is also fixed by > now. The fault handler deadlock was fixed in the usual "drop locks and > jump into slowpath" fasion, at least in drm/i915. So we can remove that whole yield/set_need_resched() mess completely ? Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/